1. Field of the Invention
The present invention relates to a wired circuit board and, more particularly, to a wired circuit board such as a suspension board with circuit or a flexible wired circuit board.
2. Description of the Related Art
In recent years, to respond to an increase in wiring density, it has been known to use a double-decker structure in which one wire and the other wire are disposed to oppose each other with an insulating layer interposed therebetween in a thickness direction as a wiring structure in a wired circuit board such as a suspension board with circuit or a flexible wired circuit board.
For example, a suspension for disk has been proposed in which, to suppress the occurrence of crosstalk in a conductive layer, a wiring portion includes a second layer (lower insulating layer) of an insulating layer, second conductors (a conductor for writing and a conductor for reading) formed on the second layer, a first layer (upper insulating layer) of the insulating layer formed on the second conductors to cover the second layer and the second conductors, and first conductors (a conductor for writing and a conductor for reading) formed on the first layer to oppose the second conductors in a thickness direction (see, e.g., Japanese Unexamined Patent Publication No. 2004-133988).